Osprey Reef · Australia · Wall · Reef
Half Way Wall
Bommies from 20 m on the lip of a thousand-metre wall.
Area photo: João D'Andretta · CC BY 4.0
Half Way Wall is a Coral Sea mooring midway between North Horn and False Entrance. The mooring sits on the edge of the wall itself, with bommies rising from around twenty metres along the lip and the main wall dropping away under the boat to over a thousand metres. Grey reef and whitetip reef sharks, dogtooth tuna and schooling bigeye trevally are what the site is known for.
Where it is and how deep
13.8830° S, 146.5670° EApproximate position — the dashed circle shows where the site lies; your operator's briefing has the mooring.
The dive
You start on the mooring, which is set on the edge of the wall, so the reef is on one side of you and open ocean on the other from the moment you leave the boat. A number of bommies rise from around twenty metres along that edge and give the dive its structure, something to work between and around, while the main wall drops away under the boat to over a thousand metres.
Grey reef sharks and whitetip reef sharks are the regulars on this stretch, with dogtooth tuna and schools of bigeye trevally rounding out what the site is known for. With nothing below you reading as a bottom, depth is a matter of personal discipline rather than topography here: the reason to dive Half Way Wall is the shallow structure along the lip and the fish that move past it, not the wall's numbers.
Marine life and season
- Reef sharks
- Trevally & jacks
- Tuna
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Off-season | Off-season | Fair | Good | Good | Good | Good | Good | Prime | Prime | Prime | Good |
Season follows Osprey Reef: Coral Sea crossings run in the calmer dry season; cyclone risk and rough seas suspend trips Jan–Feb, with hammerhead numbers building Sep–Dec.
Know before you go
- The wall under the mooring runs to over a thousand metres, so there is no visual floor to stop a descent. Agree a maximum depth before entry and watch your gauge on the blue side.
Questions divers ask
How deep is Half Way Wall?+
The bommies along the mooring edge rise from around twenty metres, which is the working depth of the dive. The main wall itself drops away under the boat to over a thousand metres, so there is no bottom to reference.
Sources
- Coral Sea, Australia dive sites — Spirit of Freedom
More dive sites in Osprey Reef
Wall
Gullies and trenches between reef turrets, and a gorgonian-filled overhang.
Wall
Blue-water swim-throughs at the lip of a 30 m drop
Ten to thirty sharks work the ledges when the drum goes in
Similar dives elsewhere
A broadclub cuttlefish on the coral, sharks and turtles out in the blue.
Sponge-covered ledges to 26 m, walked in from shore
A 50 m wall with an overhang you shoot from underneath
A 20 m wall with a sand patch crowded with sea cucumbers